Mercedes Automatic Manual Transmission Issue

[Gaz n Debz]

Hi All,

I'm having an issue with my 2004 Mercedes Sprinter based motor home, the engine is the 2.7 litre diesel and the transmission is an automatic manual system.
When I select 'Auto' I'm finding that the system can't decide what gear it wants to be in and is 'Shuttling' up and down the box causing the engine to either race away as it is in too low a gear, or struggle if in too high a gear. When accelerating quite hard, i.e. when joining a major road from a slip road, it seems to take ages to change up a gear meaning that a lot of momentum is lost - especially if going up an incline - and if I'm driving along a flat stretch of motorway/dual carriageway at 60-65mph it can't decide whether it wants to be in 5th or 6th.
If I take manual control and select a gear it will stay there until I change it - as it's in manual obviously this is what you would expect - therefore it's not stopping us from using it, but would be grateful if anyone has had any experience of this happening to them and what steps were taken to remedy it.
I appreciate it will probably mean a visit to the garage but obviously don't want to do this now, unless absolutely necessary, as we have a couple of trips away already planned.

Thanks for any information,

Gary

 

[TerryL]

First guess, low or contaminated gearbox fluid. From reading the forum it's rare to find problems with the Merc autobox and it's usually the fluid.

No experience with them, however, so "bumping" for someone to tell you how to check.

 

[WillH]

As above, classic autobox oil problem .

 

[Detnor]

As above, even on new Merecedes, first service on automatics includes a gearbox oil change.

 

[Gaz n Debz]

Thanks for the replies.
My initial thought was that it was a gearbox oil issue. When I got it serviced a few weeks ago I specifically asked that the oil and filter be changed, however I was told that as it is actually a Manual gearbox with an automatic actuator system that changes the gears it didn't need doing.
I think I may take it to a Merc specialist and ask their opinion - just hope my pockets are deep enough!!

^{_{Subscribers  do not see these advertisements}}

 

[TerryL]

Try a local Mercedes Commercial Service Centre, it is after all a commercial based vehicle. Car servicing for Mercs tends to be somewhat special, read expensive!

My neighbour found a small independant local who does nothing but Mercs, even has parts going back years. But Newcastle is probably a bit far for you. Just saying though.

 

[DavidG58]

We have the full auto Mercedes gearbox a d as suggested above already we have put to bed what seemed like serious issues with change of oil and top ups

oddly the dip stick on our gearbox is sealed, so once removed to check you need a new one

I leave it to Mertrux at annual service